One method of measuring the range between two wireless devices includes using radio frequency (RF) received signal strength (RSS) measurements. Another method includes time-of-flight (TOF) ranging that measures the RF signal TOF between two wireless devices. Because RF signals travel at the speed of light, however, one-meter accuracy requires approximately 3 nanosecond (ns) time resolution. On a low-cost, low-power system, it may be difficult to achieve this accuracy. Typical radios may only resolve the time of events at the rate of their reference clock, resulting in resolution on the order of 50 ns (15 m). As a result, special techniques and hardware may need to be employed to enable desired accuracy.
Accordingly, a need exists for devices and methods that provide more accurate and configurable physical measurements, such as distance, speed, etc., using RF devices.